ANATOMY AND CLASSIFICATION OF THE ARENICOLIDJE. 433 



in the lower portion of the littoral zone. The general colour 

 is dark velvety bottle-green, with slight yellowish and bluish 

 iridescence. The branchijB and proboscis are reddish, the 

 notopodial setas golden yellow. The specimen from Captiva 

 Key is flesh-coloured, and the one from Jamaica is black up 

 to the seventh segment, semi-transparent and almost colour- 

 less behind. 



The large American specimen of A. cristata is 360 mm. 

 long (PI. 24, fig. 30), and specimens 400 mm. long have been 

 taken at Naples (Lo Bianco, 1899, p. 484). 



According to Llitken (1864) this species (to which he gave 

 the name A. antillensis) is common on the shores of the 

 West Indies, but although Mr. J. E. Duerden, Curator of the 

 Institute of Jamaica, has searched the coast for some time he 

 has only been able to meet with one specimen, so that this 

 species is not common on the Jamaican shores. 



Of the habits of A. cristata Stimpson (1856) says, ''It 

 occurred in the third and fourth sub-regions of the littoral 

 zone, living in holes in the hard sand excavated to two feet. 

 The holes were exactly adapted to the thickness of the 

 animal, and were not furnished with a lining of any kind. 

 They extend obliquely downwards, at first perpendicularly, 

 then curving horizontally. The lower extremity is about 

 one foot below the surface. Each worm was found head 

 downwards in its burrow. During the hitter part of March 

 we frequently observed in and about the holes of this animal 

 great quantities of a soft transparent jelly filled with minute 

 brownish specks, which proved to be the eggs." Of these 

 egg-masses Professor E. B. Wilson (1883) gives an interest- 

 ing account. " The eggs are embedded in huge gelatinous 

 masses, which assume various forms as they are swayed to 

 and fro by the tide. A common form is irregularly cylin- 

 drical, three or four feet long and as many inches wide. 

 Sometimes they are rounded and shapeless, lying flat on the 

 sand ; in other cases they are as long as six feet and more, 

 and from one to three inches in diameter. The eggs are 

 small, '13 mm. in diameter, nearly spherical or slightly ovoid. 



